In the past, flexible pouches of relatively stable thermoplastic material have been provided for use in the packaging, preservation and dispensing of fluent materials such as comestible products, medicinal preparations and the like in liquid, powdery or granular form.
In most instances, the fluent material is introduced into the pouch or container after a portion of the pouch has been formed from a web of thermoplastic material of indefinite length and thereafter the pouch is sealed and separated from the web so that individual pouches may be packaged and shipped. Normally, the pouches are made and filled in a vertical form/fill/seal machine in either a continuous or intermittent operation by folding the web of thermoplastic material in half and passing the material through the vertical machine with the folded edge being disposed vertically and forming one side of the pouch. Then the edge opposite the fold is sealed to form the other side. Thereafter, a horizontal seal is made to close the top of a lower pouch and the bottom of a contiguous upper pouch and simultaneously separate the lower pouch from the web of material. The vertical form/fill/seal machine normally is preferred due to the fact that the pouches may be formed about a fixed vertically disposed former or filling tube which obviates the necessity of providing apparatus for opening the pouches for filling purposes.
Some efforts have been made to make and fill the pouches in a horizontal form/fill/seal machine; however, the problem of opening and filling the pouches has resulted in more complicated and sophisticated machinery and normally has reduced the speed of production. Some examples of this type of equipment is shown by U.S. Pat. Nos. 3,246,444 to Paisley; 3,269,278 to Olstad; 3,453,799 to Cloud et al; 3,537,225 to Fields; 3,599,388 to Feingold; 3,618,286 and 3,779,449 to Membrino; and 3,817,017 to Titchenal.
Although the preferred method of forming and filling thermoplastic pouches is in a vertical form/fill/seal machine, there are instances when such vertical machine is not satisfactory. For example, when the pouch to be made is relatively small or the longitudinal dimension of the pouch is greater than twice the dimension measured along the fold, it is preferable to form, fill and seal the pouch in a horizontal process. This is primarily due to the fact that when the fluent material is introduced into the side of an elongated relatively narrow pouch, insufficient clearance or head room is provided to permit the pouch to be properly sealed.
In a horizontal form/fill/seal machine, the fold of the material is located at the bottom of the pouch and a pair of vertical side seals are made prior to the introduction of the fluent material and the top of the pouch is sealed after the material has been introduced into the pouch.
In some instances, it is desirable to attach a material dispensing fitment to the pouch as the pouch is being formed and such fitment serves to assist in the partial or complete dispensing of the material when desired. In some cases, the fitment also serves to assist in filling the pouch. Some examples of pouches having fitments are disclosed in my copending application Ser. No. 389,099, Gussetted Bottom POuch now U.S. Pat. No. 4,452,378, and my previous U.S. Pat. Nos. 3,894,381 and 4,246,062; as well as U.S. Pat. Nos. 2,850,422 to Welch, Jr.; 2,999,387 to Andelin; 3,244,576 to Swartz; 3,554,256 to Anderson; 3,652,047 to Waage; 3,994,412 to Difiglio; and, 4,049,034 to Vcelka.
Heretofore, substantial difficulty has been encountered in attaching a fitment to the fold of a pouch being made in a horizontal form/fill/seal machine because the polymeric thermoplastic web must be reshaped to a form that will provide a flat spot that otherwise would be a fold. The web, which is being stretched flat in the machine, resists the required reshaping.